/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.http.client.reactive;

import java.net.URI;
import java.util.function.Consumer;
import java.util.function.Function;

import reactor.core.publisher.Mono;
import reactor.ipc.netty.http.client.HttpClient;
import reactor.ipc.netty.http.client.HttpClientOptions;
import reactor.ipc.netty.http.client.HttpClientRequest;
import reactor.ipc.netty.http.client.HttpClientResponse;
import reactor.ipc.netty.options.ClientOptions;

import org.springframework.http.HttpMethod;

/**
 * Reactor-Netty implementation of {@link ClientHttpConnector}.
 *
 * @author Brian Clozel
 * @see reactor.ipc.netty.http.client.HttpClient
 * @since 5.0
 */
public class ReactorClientHttpConnector implements ClientHttpConnector {

    private final HttpClient httpClient;


    /**
     * Create a Reactor Netty {@link ClientHttpConnector}
     * with default {@link ClientOptions} and HTTP compression support enabled.
     */
    public ReactorClientHttpConnector() {
        this.httpClient = HttpClient.builder()
                .options(options -> options.compression(true))
                .build();
    }

    /**
     * Create a Reactor Netty {@link ClientHttpConnector} with the given
     * {@link HttpClientOptions.Builder}
     */
    public ReactorClientHttpConnector(Consumer<? super HttpClientOptions.Builder> clientOptions) {
        this.httpClient = HttpClient.create(clientOptions);
    }


    @Override
    public Mono<ClientHttpResponse> connect(HttpMethod method, URI uri,
            Function<? super ClientHttpRequest, Mono<Void>> requestCallback) {

        if (!uri.isAbsolute()) {
            return Mono.error(new IllegalArgumentException("URI is not absolute: " + uri));
        }

        return this.httpClient
                .request(adaptHttpMethod(method),
                        uri.toString(),
                        request -> requestCallback.apply(adaptRequest(method, uri, request)))
                .map(this::adaptResponse);
    }

    private io.netty.handler.codec.http.HttpMethod adaptHttpMethod(HttpMethod method) {
        return io.netty.handler.codec.http.HttpMethod.valueOf(method.name());
    }

    private ReactorClientHttpRequest adaptRequest(HttpMethod method, URI uri, HttpClientRequest request) {
        return new ReactorClientHttpRequest(method, uri, request);
    }

    private ClientHttpResponse adaptResponse(HttpClientResponse response) {
        return new ReactorClientHttpResponse(response);
    }

}
